In the prior art a single print engine/controller controls a single printhead. However this solution does not scale well for wider format printheads, for high resolution input images, or for faster printing. For wide format printheads the controller chip has to be made to run faster in order to print the same number of printlines, each of which is now longer. Or if the printhead is to run faster the print controller has to be run at a faster clock speed. Or if the input image has a higher resolution then the controller chip has to have more buffers internally or run faster or both in order to process the effectively larger input image since it is a higher resolution.
A range of printer types have evolved wherein an image is constructed from ink selectively applied to a page in dot format. In U.S. Pat. No. 6,045,710 titled ‘self-aligned construction and manufacturing process for monolithic printheads’ to the inventor Kia Silverbrook there is set out an assessment of the prior art to drop on demand printers along with its manufacturing process.
Various methods, systems and apparatus relating to the present invention are disclosed in the following co-pending United States patent applications filed by the applicant or assignee of the present invention on 23 May 2000:
09/575,197,09/575,195,09/575,159,09/575,132,09/575,123,09/575,148,09/575,130,09/575,165,09/575,153,09/575,118,09/575,131,09/575,116,09/575,144,09/575,139,09/575,186,09/575,185,09/575,191,09/575,145,09/575,192,09/609,303,09/610,095,09/609,596,09/575,181,09/575,193,09/575,156,09/575,183,09/575,160,09/575,150,09/575,169,09/575,184,6,502,614,09/575,180,09/575,149,6,549,935,09/575,187,09/575,155,6,591,884,6,439,706,09/575,196,09/575,198,09/575,178,6,428,155,09/575,146,09/608,920,09/575,174,09/575,163,09/575,168,09/575,154,09/575,129,09/575,124,09/575,188,09/575,189,09/575,162,09/575,172,09/575,170,09/575,171,09/575,161,10/291,716,6,428,133,6,526,658,6,315,399,6,338,548,6,540,319,6,328,431,6,328,425,09/575,127,6,383,833,6,464,332,6,439,6936,390,591,09/575,152,6,328,417,6,409,323,09/575,114,6,604,810,6,318,920,6,488,422,09/575,108,09/575,10909/575,110.
In addition, various methods, systems and apparatus relating to the present invention are disclosed in the following co-pending United States patent applications filed simultaneously by the applicant or assignee of the present invention: U.S. Pat. Nos. 6,398,332, 6,394,573, 6,622,923.
The disclosures of these co-pending applications are incorporated herein by cross-reference. Each application is temporarily identified by its docket number. This will be replaced by the corresponding USSN when available.
Of particular note are co-pending U.S. patent application Ser. Nos. 09/575,152, 6,428,133, 6,526,658, 6,328,417, 6,390,591, which describe a microelectomechanical drop on demand printhead hereafter referred to as a Memjet printhead.
The Memjet printhead is developed from printhead segments that are capable of producing, for example, 1600 dpi bi-level dots of liquid ink across the full width of a page. Dots are easily produced in isolation, allowing dispersed-dot dithering to be exploited to its fullest. Color planes might be printed in perfect registration, allowing ideal dot-on-dot printing. The printhead enables high-speed printing using microelectromechanical ink drop technology.
In addition, co-pending U.S. patent application Ser. Nos. 09/575,108, 09/575,109, 09/575,110 6,398,332, 6,394,573, 6,622,923 describe a print engine/controller suited to driving the above referenced page wide printhead.
A single print engine/controller (PEC) chip is capable of driving a printhead of the above referenced type, printing a dithered version of a 320 ppi contone image over a 12 inch printhead. It is desirable to be able to print higher resolution images for higher quality output. It is desirable to be able to run the printhead faster.